Serum adipokine levels predictive of liver injury in non-alcoholic fatty liver disease.

Objective: The aim of this study was to determine whether serum levels of adipokines, including the ratio of serum adiponectin to leptin (A/L) levels could predict the severity of liver injury in patients with non-alcoholic fatty liver disease (NAFLD).

Methods: Fifty-seven patients with biopsy-proven non-alcoholic steatohepatitis (NASH) (mean age 51+/-12, sex ratio 1), 17 with simple steatosis (mean age 47+/-12, sex ratio 1.4) and 10 controls without steatosis (mean age 51+/-11, sex ratio 4) were investigated. In all subjects, serum concentrations of triglycerides, ultrasensitive C reactive protein, leptin, adiponectin, soluble tumour necrosis factor receptor 1, interleukin (IL)-6 and Homeostasis Model Assessment Method (HOMA) were measured. Hepatic expression of adiponectin and its two receptors was assessed by quantitative reverse transcriptase polymerase chain reaction.

Results: Body mass index (BMI) and HOMA were correlated positively with leptin levels (r=0.44 and 0.28 respectively) and negatively with the A/L ratio (r=0.51 and 0.41 respectively). Independent parameters associated with NASH vs steatosis were HOMA>3 [odds ratio (OR)=6.9] and A/L ratio <1.4 10(3) (OR=5.2). The combination of HOMA with A/L ratio showed an area under the receiver operating characteristic curve of 0.82 for distinguishing between NASH and steatosis. Extensive portal fibrosis was present in 17 (23%) patients with NAFLD. Three independent parameters were associated with fibrosis: age (OR=1.1), BMI (OR=1.3) and high IL-6 levels (OR=1.6). The hepatic expression of adiponectin receptor 2 was significantly higher in patients with NASH compared with controls and was related with necroinflammatory injury.

Conclusions: This study shows that in patients with NAFLD, the combination of HOMA with A/L ratio may be a useful non-invasive approach to appreciate the severity of liver damage.